Bracket Hint

.btn-bracket-hint {
  display: inline-block;
  padding: 12px 10px;
  border: none;
  background: transparent;
  color: #e2e8f0;
  font-family: inherit;
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
}
.btn-bracket-hint::before {
  content: "[";
  display: inline-block;
  margin-right: 10px;
  color: #38bdf8;
  opacity: 0;
  transform: translateX(10px);
  transition: opacity 0.25s ease, transform 0.25s ease;
}
.btn-bracket-hint::after {
  content: "]";
  display: inline-block;
  margin-left: 10px;
  color: #38bdf8;
  opacity: 0;
  transform: translateX(-10px);
  transition: opacity 0.25s ease, transform 0.25s ease;
}
.btn-bracket-hint:hover::before,
.btn-bracket-hint:hover::after {
  opacity: 1;
  transform: translateX(0);
}